Crossbows have been used for centuries for both hunting and recreation. They are typically characterized by horizontal limbs mounted on a stock with a bowstring that is drawn to store energy that is transferred to a bolt upon firing. The bowstring is held in a string catch that holds the bowstring until the user is ready to fire. When the user is ready to shoot the bolt, the user pulls a trigger. Upon pulling the trigger, a series of interactions occurs between components of a trigger assembly, allowing the bowstring to be released from the string catch and allowing transfer of the energy stored in the bowstring to the bolt.
There are several different designs of crossbows. A recurve crossbow has a bowstring attached directly to limbs that extend from the body of the crossbow. When the bowstring is drawn, the limbs deflect and store potential energy that is transferred to the bowstring and a loaded arrow when the crossbow is fired. A compound crossbow has a set of wheels or cams attached to its limbs. A cabling system attached to the wheels or cams is used to bend the limbs as the bowstring is drawn.